The tractors and combine that has cummins in we have had good luck with, the 903 no problem except a oil cooler 5000 hours, 8.3 in combine we got used so don't now, 8.3 in tractor we put 4000 hour on it of 9000 we replace fuel pump no other and I think it is gitting a little week, 2 tractors with 5.9 at 7000 and 8000 hours still going strong, the 3.9 in the little tractor had the ingictor pump gone through this year (had fuel leek only) the engine still gone strong the tractor is gitting tired. The shop that my family partner in they went to cummis school so they could do the work on the engines, but they had problem with agco and now are kick out of agco, I don't know if it was agco or there stupid partner.